Field of the Invention
Embodiments of the present invention generally relate to wireless power transfer, and more particularly, to simultaneously wirelessly charging portable chargeable devices based on wireless inductive power transfer with enhanced qualitative and quantitative parameters, such as economic feasibility, easy usability, seamless free positioning capability, minimal cross-interference and maximal power transfer efficiency.
Description of the Related Art
Wireless or contactless battery charging has undergone some developments in recent years owing to the enhanced user experience and reliability of not having to use connectors, and the advantages of having universal wireless chargers for any kind of electronic devices, like laptops, mobiles etc.
One major problem is free positioning of portable devices on a wireless charger thereby facilitating seamless charging of the portable devices thereupon.
Some solutions for charging multiple mobile phones simultaneously provide for a common transmitter pad, wherein one or more independent charging systems may be used. However, the seamless free positioning capability is lost on account of physical demarcation between the independent charging systems.
In certain scenarios involving charging of multiple mobile phones using a common charger pad, highly resonant wireless power transfer provides a better user experience in terms of three dimensional free positioning capabilities. However, the total cost of the equipment turns out to be higher on account of usage of the advanced technology, in addition to the separate communications requirements that needs to be built into the wireless charger. Thus, highly resonant wireless power transfer and similar technologies may not find wide acceptance in a worldwide consumer market, unless costs are acceptable. Additionally, the highly resonant wireless power transfer and similar technologies may fail to charge existing mobile phones that already have wireless power capability.
In certain scenarios involving charging of at least one of a single portable computing and communications device using the free positioning capability, and at least a pair of the portable computing and communication devices, there is likelihood or probability of occurrence of one or more events, such as at least one of power transfer and communications events, at least one of simultaneously and separately, owing to at least a pair of transmitter coils comprising the transmitter coil array, in any point in time. In general, an electromagnetic shield that serves the transmitter coils, in entirety, as a common electromagnetic shield is used. The electromagnetic shield maximizes the power transfer efficiency via directing the flux paths. However, as a consequence, the electromagnetic shield provides for a common impedance path thereby resulting in cross-interference amid two or more transmitter coils.
One solution to the problem of cross-interference is introduction of a gap in the electromagnetic shield thereby facilitating elimination of cross-interference amid two or more transmitter coils. However, the introduction of the gap may have an impact on the efficiency of power transfer, and is thus not recommended.
Therefore, there is still a need for the design and implementation of methods and systems for streamlined, simultaneous wireless charging of portable chargeable devices based on wireless inductive power transfer with enhanced qualitative and quantitative parameters, such as economical, easy usability, seamless free positioning capability, minimal cross-interference and maximal power transfer efficiency.